4 i 3 THE POPULAR SCIENCE MONTHLY. 



passes through the book, and thus reaches the sensory nerve, and that, 

 but for the intervening book, it would not pass that way? Under 

 some circumstances, it might be that a conductor would facilitate the 

 passage of a " something " which would not pass through the air, but 

 in this case there is the difficulty of getting this "something" to the 

 book, and then of sending it forward through the air. The only alter- 

 native seepis to be to suppose that when there was no intervening 

 book, a " something " passed to the frog which was necessary to cause 

 it to jump directly forward, the passage of which the book prevented. 

 Neither of these hypotheses seems satisfactory, even if no objection is 

 made to the unknown " something." 



To those skilled in scientific investigation it may not appear im- 

 portant, but I apprehend that many, like myself, not familiar with its 

 modes, will regret that the experiment in this case was not pushed 

 somewhat further. To find, for instance, what would be the effect 

 when the obstruction extended equally to the right and to the left ? 

 What if it extended indefinitely both ways? And what, when it 

 made an entire circle around the frog in the centre ; and what if in 

 different positions other than the centre. 



But, even admitting, in all the cases, all that Prof. Huxley claims 

 as ascertained facts, what does it all amount to further than that he 

 has brought to light some additional phenomena which, like the move- 

 ments of the material univtrse and the pulsations of the heart, must 

 be referred to some inscrutable agency ? He who believes only in 

 intelligent power refers them, with all else that he does not effect by 

 his own efforts, and which he regards as beyond the power of any 

 known embodied intelligence, to a Superior Intelligence, acting 

 through the instrumentality of matter or otherwise ; while he who 

 believes only in material causation attributes them to the influence of 

 matter, in some form or some mode of its movement differing from 

 those forms and modes which are familiar to him. Nor is it material 

 how many steps there may be between the power applied and the 

 effect. If there are three or thirty ivory balls in a right line, and the 

 first of them is put in motion causing each one successively to impinge 

 on the next, the final effect of motion in the last is caused by the power 

 applied to the first. We may by our own efforts put the alleged power 

 of matter in action, or may thus act through the uniform modes of 

 God's action. 



In voluntary muscular movement the intermediate effect of a flow 

 of blood to the contracting muscle has long been known; now, the 

 propagation of molecular movement is ascertained. That we are not 

 conscious of the movement of the molecules indicates (though far from 

 conclusively) that we do not ourselves move them, but this does not 

 indicate that the muscular movement is not the result of our own effort 

 working through other agencies. That he who throws the stone which 

 kills a bird does not know what curve the stone will describe, nor by 



